avalonmailstore.java

java 开发的邮件服务器平台。支持以下协议。 协议可以修改为自己的专门标识

/***********************************************************************
 * Copyright (c) 2000-2004 The Apache Software Foundation.             *
 * All rights reserved.                                                *
 * ------------------------------------------------------------------- *
 * Licensed under the Apache License, Version 2.0 (the "License"); you *
 * may not use this file except in compliance with the License. You    *
 * may obtain a copy of the License at:                                *
 *                                                                     *
 *     http://www.apache.org/licenses/LICENSE-2.0                      *
 *                                                                     *
 * Unless required by applicable law or agreed to in writing, software *
 * distributed under the License is distributed on an "AS IS" BASIS,   *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or     *
 * implied.  See the License for the specific language governing       *
 * permissions and limitations under the License.                      *
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package org.apache.james.core;

import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfiguration;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.logger.LogEnabled;
import org.apache.james.services.MailRepository;
import org.apache.james.services.MailStore;
import org.apache.james.services.SpoolRepository;

import java.util.HashMap;

/**
 * Provides a registry of mail repositories. A mail repository is uniquely
 * identified by its destinationURL, type and model.
 *
 */
public class AvalonMailStore
    extends AbstractLogEnabled
    implements Contextualizable, Composable, Configurable, Initializable, MailStore {

    // Prefix for repository names
    private static final String REPOSITORY_NAME = "Repository";

    // Static variable used to name individual repositories.  Should only
    // be accessed when a lock on the AvalonMailStore.class is held
    private static long id;

    // map of [destinationURL + type]->Repository
    private HashMap repositories;

    // map of [protocol(destinationURL) + type ]->classname of repository;
    private HashMap classes;

    // map of [protocol(destinationURL) + type ]->default config for repository.
    private HashMap defaultConfigs;

    /**
     * The Avalon context used by the instance
     */
    protected Context                context;

    /**
     * The Avalon configuration used by the instance
     */
    protected Configuration          configuration;

    /**
     * The Avalon component manager used by the instance
     */
    protected ComponentManager       componentManager;

    private SpoolRepository inboundSpool;

    /**
     * @see org.apache.avalon.framework.context.Contextualizable#contextualize(Context)
     */
    public void contextualize(final Context context)
            throws ContextException {
        this.context = context;
    }

    /**
     * @see org.apache.avalon.framework.component.Composable#compose(ComponentManager)
     */
    public void compose( final ComponentManager componentManager )
        throws ComponentException
    {
        this.componentManager = componentManager;
    }

    /**
     * @see org.apache.avalon.framework.configuration.Configurable#configure(Configuration)
     */
    public void configure( final Configuration configuration )
        throws ConfigurationException
    {
        this.configuration = configuration;
    }

    /**
     * @see org.apache.avalon.framework.activity.Initializable#initialize()
     */
    public void initialize()
        throws Exception {

        getLogger().info("JamesMailStore init...");
        repositories = new HashMap();
        classes = new HashMap();
        defaultConfigs = new HashMap();
        Configuration[] registeredClasses
            = configuration.getChild("repositories").getChildren("repository");
        for ( int i = 0; i < registeredClasses.length; i++ )
        {
            registerRepository((Configuration) registeredClasses[i]);
        }


        Configuration spoolRepConf
          = configuration.getChild("spoolRepository").getChild("repository");
        try {
           inboundSpool  = (SpoolRepository) select(spoolRepConf);
        } catch (Exception e) {
            getLogger().error("Cannot open private SpoolRepository");
            throw e;
        }
        if (getLogger().isInfoEnabled()) {
            getLogger().info("SpoolRepository inboundSpool opened: "
                              + inboundSpool.hashCode());
            getLogger().info("James MailStore ...init");
        }
    }

    /**
     * <p>Registers a new mail repository type in the mail store's
     * registry based upon a passed in <code>Configuration</code> object.</p>
     *
     * <p>This is presumably synchronized to prevent corruption of the
     * internal registry.</p>
     *
     * @param repConf the Configuration object used to register the
     *                repository
     *
     * @throws ConfigurationException if an error occurs accessing the
     *                                Configuration object
     */
    public synchronized void registerRepository(Configuration repConf)
        throws ConfigurationException {
        String className = repConf.getAttribute("class");
        boolean infoEnabled = getLogger().isInfoEnabled();
        Configuration[] protocols
            = repConf.getChild("protocols").getChildren("protocol");
        Configuration[] types = repConf.getChild("types").getChildren("type");
        for ( int i = 0; i < protocols.length; i++ )
        {
            String protocol = protocols[i].getValue();

            // Get the default configuration for these protocol/type combinations.
            Configuration defConf = repConf.getChild("config");

            for ( int j = 0; j < types.length; j++ )
            {
                String type = types[j].getValue();
                String key = protocol + type ;
                if (infoEnabled) {
                    StringBuffer infoBuffer =
                        new StringBuffer(128)
                            .append("Registering Repository instance of class ")
                            .append(className)
                            .append(" to handle ")
                            .append(protocol)
                            .append(" protocol requests for repositories of type ")
                            .append(type);
                    getLogger().info(infoBuffer.toString());
                }
                if (classes.get(key) != null) {
                    throw new ConfigurationException("The combination of protocol and type comprise a unique key for repositories.  This constraint has been violated.  Please check your repository configuration.");
                }
                classes.put(key, className);
                if (defConf != null) {
                    defaultConfigs.put(key, defConf);
                }
            }
        }

    }

    /**
     * This method accept a Configuration object as hint and return the
     * corresponding MailRepository.
     * The Configuration must be in the form of:
     * <repository destinationURL="[URL of this mail repository]"
     *             type="[repository type ex. OBJECT or STREAM or MAIL etc.]"
     *             model="[repository model ex. PERSISTENT or CACHE etc.]">
     *   [addition configuration]
     * </repository>
     *
     * @param hint the Configuration object used to look up the repository
     *
     * @return the selected repository
     *
     * @throws ComponentException if any error occurs while parsing the 
     *                            Configuration or retrieving the 
     *                            MailRepository
     */